186 Sciridifc Iiii<lli(j<iice. 



torial physical characters are, further, classified into those of 

 higher andlower symmetry. The former are called " ellipsoidal 

 characters " because their numerical values for all possible direc- 

 tions are determined by at most three different values in direc- 

 tions at right angles, corresponding in general to the axes of an 

 ellipsoid. Here belong, for example, the optical characters, 

 according to which all crystals fall into five divisions. The 

 bivectorial characters of lower symmetry embrace these con- 

 cerned with elasticity and cohesion and the lowest grade of all is 

 shown by those involved in the molecular growth and resulting 

 structure of the crystal, where thirty-two classes are required to 

 embrace all possible types. The discussion in succession of all 

 the various characters, beginning with those involving light, is 

 clear and complete. The subject of the molecular structure of 

 crystals, from the theoretical side, is also clearly presented, and 

 it is shown how the fundamental laws of rational indices and 

 zones follow. The second half of the volume is- devoted to the 

 description of the successive systems, with the various classes 

 falling under them and the special forms belonging to each. The 

 methods employed in the investigation of crystals are treated in 

 the last one hundred and fifty pages. 



19. Preliminary Notice of a New Meteorite from Texas; by 

 Kenneth S. Howard (Communicated). — ;A new aerolite from 

 the Staked Plains of northwestern Texas has just been secured 

 by Ward's Natural Science Establishment. It will be known as 

 the Estacado, having fallen near the place of that name in 1882. 

 The following results are taken from an unfinished analysis by 

 Mr. John M. Davison : 



Specific gravity 3 - 63. Metallic part 16*41 per cent. Stony 

 part 83 - 59 per cent, of which 53 - 61 per cent is insoluble in HC1 

 and 29-98 per cent is soluble. The analysis of the metallic por- 

 tion calculated to 100 per cent is 



Fe 89-45^ 



Ni , 9-99 



Co -56 



P trace 



Cu trace 



100$ 



A complete account will be published shortly. 



20. Miner alogical Survey of Ceylon, Report for 190 If. : by A. 

 K. Coomaraswamy, Director. Pp. 21 with map and 3 plates. — ; 

 This Report gives much valuable information in regard to the 

 occurrence of gems and rare minerals in Ceylon, including the 

 remarkable thorianite. An interesting occurrence is described 

 on the Haldummulla estate, where corundum occurs in violet, 

 pink and purplish crystals loose in the soil, and also in blocks of 

 a sillimanite rock. These were not found in place, but doubtless 



